Year	mm per year
1962	2880
1963	2880
1964	2880
1965	2880
1966	2880
1967	2880
1968	2880
1969	2880
1970	2880
1971	2880
1972	2880
1973	2880
1974	2880
1975	2880
1976	2880
1977	2880
1978	2880
1979	2880
1980	2880
1981	2880
1982	2880
1983	2880
1984	2880
1985	2880
1986	2880
1987	2880
1988	2880
1989	2880
1990	2880
1991	2880
1992	2880
1993	2880
1994	2880
1995	2880
1996	2880
1997	2880
1998	2880
1999	2880
2000	2880
2001	2880
2002	2880
2003	2880
2004	2880
2005	2880
2006	2880
2007	2880
2008	2880
2009	2880
2010	2880
2011	2880
2012	2880
2013	2880
2014	2880
2015	2880
2016	2880
2017	2880
2018	2880
2019	2880
2020	2880